Baseball may be loved without statistics, but it cannot be understood without them."" Thorn (editor of The National Pastime) and Palmer (chief statistician for the American League) have undertaken, moreover, to devise a generation-spanning system that will permit meaningful comparisons of the abilities of players from different eras. They track the history of the game's traditional statistics--from the late 1860s, when an English cricket enthusiast named Henry Chadwick began compiling box scores, through the computer-aided development of their own innovative methods. Along the way, they note the shortcomings of many long-accepted measures of accomplishment. Batting averages, for example, are dismissed as overly egalitarian in that a one-out bunt single in the ninth inning, with nobody on base and the hitter's team behind by six runs, counts the same as Bobby Thomson's ""shot heard 'round the world."" Instead, Thorn and Palmer offer their linear weights system (LWTS)--based on the logical premise that wins and losses are in some way . proportional to runs scored and runs allowed; in turn, runs are proportional to the events which go into their creation (hits, stolen bases) or prevention (pitching, fielding). By adjusting for park differences, league averages, and other normalizing factors, Thorn and Palmer are able to roam across time to reach frequently provocative conclusions. Few fans, of course, will be surprised to learn that Babe Ruth was the game's greatest hitter by LWTS lights--but Mike Schmidt, we hear, may eventually claim Ted Williams' runner-up spot. Where pitchers are concerned, Cy Young and Walter Johnson earned their reputations, the authors find, while Harry Brecheen, Hal Newhouser, and Hoyt Wilhelm languish in undeserved obscurity. Thorn and Palmer also explore ""The Book,"" an unwritten collection of managerial maneuvers held to be high percentage plays. According to their data, sacrifice bunts are usually a losing proposition. Further, pitching represents but 44 percent--not 70 percent or more--of the game, with fielding at 6 percent and batting at 50 percent. With some subjective asides, as well as a wealth of equations, charts and tabular material: a revisionist tract of real merit that could become a manual for all seasons (however demanding the math for certain, probability-theory stretches).